The instant invention relates to apparatus for clearing a paper jam between two rollers, and more particularly to a pivoting cover for such rollers which can be used to separate the two rollers from each other and facilitate access to the area of the rollers to enable jam clearance. The invention is particularly applicable to optical machine readers used in inserter systems.
Photodetection of indicia on forms and the like is known. In such systems, a narrow beam of light is focused as a spot or slit of light on the relevant field to be scanned and is moved over the field, either by the deflection of the beam or movement of the form. Light reflected from, or transmitted through, the form is focused on a photocell or other photodetector so that indicia may be detected as variations in the photocell output. Typically, photocell outputs are small so that the photocell is connected to an amplifier and the amplified output is further processed by the system.
One application of photodetection is in the control of inserter systems, which separate and process discrete documents, assemble the documents and other materials into batches to be mailed together and insert the batches into envelopes. Inserting systems are typically controlled according to information, for example "dash codes", encoded on control documents. Dash codes consist of lines, normal to the direction of motion of the printout, which are printed on the control document, typically on the sprocket strips of the printout. The field containing the dash codes is scanned by reflected light as the control document is received by the inserter system and the presence or absence of lines of encoded information defines the operations relating to that control document.
A scanning apparatus used in conjunction with inserting machines having various document feeders is known as an "optical mark reader" or OMR. The OMR requirement for inserting machines has existed for some time and optical scanner technology has developed to satisfy this requirement. For example, in U.S. Pat. No. 4,659,939 issued to John L. Lorenzo on Apr. 21, 1987 and assigned to the assignee of the present invention, there is disclosed an optical scanning system, commonly referred to as an OMR scanner, including an amplifier which automatically adjusts the background reference level and a photodetector which detects light reflected from or transmitted through objects such as code markings on forms. It is well known to use such an OMR scanner in conjunction with document feeders in console inserter systems.
An OMR includes a pair of feed rollers to advance the of the OMR. Because of the nature of paper feeding, occasionally paper will become jammed in the OMR, and because of the lack of space in the OMR, removal of the jammed paper is difficult to effect.
The instant invention is therefore intended to facilitate clearance of paper jams in the OMR, or any other unit in which there is minimal space to clear jams or to provide additional apparatus to facilitate jam clearance.